Three-year trial was carried out at Zabcice u Brna (185 m above sea level,average annual temperature 10.4 degrees C, average annual precipitation 463 mm, clay loam, fluvi-eutric gley soil) aimed at comparing the effect of different technology of soil preparation for spring barley before sowing on soil physical properties, yield and grain quality. Methodology of the trial was made up to find the differences between traditional and reduced tillage technologies. Factors which were verified: 1) tillage to a depth of 150 or 200 mm; 2) soil in spring before sowing treated by rotary harrow (STEYR-Lely of 6 mm engagement) or smoothed; 3) rolled (smooth field-roller VAH-5, without filling) before sowing or not rolled at all. The combination of tillage to 200 mm, soil smoothed and rolled before sowing in the spring, was considered as comparing treatment. A whole area of the trial was treated in the spring before sowing by a rate of 60 kg N.ha(-1). The experimental area was sown in the spring as soon as the conditions allowed it - at suitable soil moisture, by the Perun variety. The grain was deposited at a 30 mm depth. The sowing rate was 4.5 million germinating seed grains. Neither significant infestation of barley by diseases and pests, nor lodging occurred in any year. All values presented in tables are means for three experimental years with marking the value of significance based on the analysis of variance. Results of trial can be summed up into the following items: In the treatment when rotary harrow was used higher porosity (Tab. III) was found out in a whole layer up to 200 mm in the term 1 and in upper layer of a part of profile up to 100 mm in the term 2 (Tab. IV) from which faster infiltration of precipitation water can be assumed. In the treatment when rotary harrow was used, lower relative humidity in the surface layer up to 100 mm was found and the other way round, higher relative humidity was ascertained in a 100 to 200 mm layer in the term 2 (Tabs V and VI), from what follows that root system of barley should have higher deficit of water. Highest percentage of agronomically most valuable aggregates (Tab. VII) occurred in treatments when rotary harrow was used (highest amount of aggregates of size 2 to 5 mm and the lowest percentage of lumps and non-structural particles). A depth of soil preparation had significant impact on the yield, higher yield was acquired with tillage up to 150 mm depth (4.93 t.ha(-1)) in distinction from tillage to a 200 m depth (4.79 t.ha(-1). Highly significant difference was found out between soil treatment by rotary harrow and smoothing harrow in percentage of front grain (Tabs I and II, Fig. 1) and in the content of proteins (Tab. VIII). Significant differences were found out in 1 000-kernel weight (Tab. VIII) and starch content (Tab. IX). Statistically insignificant difference was found in extract (Tab. VIII). In all investigated traits shown in Tabs I, II and VIII more favourable values were attained when rotary harrow was used. The yield and quality of spring barley grain were significantly influenced by the course of weather conditions of the year (Tab. IX). The highest yield and percentage of front grain (Tab. IX) were achieved in 1991, the most favourable content of proteins was in 1992, the highest content of starch and extract was acquired in this year. The most favourable values of bulk density and 1 000-kernel weight were in 1993. Significance of differences between treatments for grain yield (size of caryopses above 2.5 mm) are presented in Fig. 1. Various types of hatching shows that statistically significant difference based upon results of LSD analysis in all three years was between treatments: tillage 200 mm, smoothing, not-rolled and tillage 200 mm, rotary harrow, not-rolled. The difference in the grain yield - size of caryopses above 2.5 mm (between values 2.7 t.ha(-1) and 3.3 t.ha(-1)) amounts to 0.6 t.ha(-1), consequently an increase is 19% (Tab. II). In treatment with combination of factors: tillage up to 150 mm depth, where soil was treated only by rotary harrow and was not rolled, higher yields and better quality of malting barley were acquired compared with the other tested treatments. This combination can be recommended for practice for conditions of transfer of heavy and medium soils in maize-production type.
